My thoughts are with Red's family and his friends. It is always sad to hear such news.
Having lost my
father to pancreatic cancer, I can tell you that often it is slow-growing and usually not diagnosed until very late...and is always terminal. People with pancreatic cancer often experience "health issues" which do not get associated with the cancer until it is finally found. It is quite likely that Red had been feeling unwell for quite some time, but the doctors couldn't pinpoint the source.
I offer my heartfelt sympathies to Red's family, friends and fans.